Tight security in Shanghai as Federer appears after death threat

Roger Federer is flanked by security guard as he arrives for the ceremonial draw for the Shanghai Masters in China.

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Security stepped up at Shanghai Masters in China

Top seed Roger Federer subject of online death threat

Federer makes public appearances Saturday despite threat

Bidding to protect No.1 ranking from Novak Djokovic

World No.1 Roger Federer arrived at the Shanghai Masters event in China Saturday amid tightened security after an online death threat against the Swiss superstar.

Federer was flanked by security guards as he made a public appearance to make the draw for the prestigious event with fellow tennis star Lleyton Hewitt.

He later visited an exhibition in the city where some of his Wimbledon memorabilia is on display.

A tournament spokesman told CNN: "We are fully aware of the comments that have been made and we take all such issues seriously.

"The Shanghai Rolex Masters has security in place for our players and every precaution is taken to make sure players are kept safe and comfortable and allowed to do the job they are here for; to play tennis and provide their fans with the thrill of watching them in action."